\begin{tikzpicture}[>=Stealth]
    \draw [->] (-3.5,0) -- (3.5,0) node[anchor=north] {$x$};
    \draw [->] (0,-2) -- (0,2) node[anchor=east] {$y$};
    \node at (0.3,-0.3) {$O$};
    \draw (0,1.6) .. controls(0.8,1.6) and (1.3,-1.5) .. (2.5,0.3);
\end{tikzpicture}
